Regulating means for refrigerating systems



May 5, 1936. G. H. WOODARD REGULATING MEANS FOR REFRIGERATING SYSTEMS Filed March 29, 1935 INVENTOR. Geoz'ZeHH bmiard Hrs ATTOR EY.

' of the water-vapor type,

Patented May 5, 1936 UNITED STATES REGULATING MEANS FOR anmrcsmrnvc SYSTEMS George H. Woodard, Phillipsburg, N. J., assignor to Ingersoll-Rand Company,

Jersey City, N. J.,

a corporation of New Jersey Application March 29, 1935, Serial No. 13,842

2 Claims. (01. 62-152) This invention relates to refrigerating systems, and particularly to means for regulating the flow of a liquid refrigerant in the conduits or pipes that carry the refrigerant when the system is in operation.

An object of the invention is to control the circulation of the refrigerant so as to avoid surging or pulsating thereof, thus keeping the level of the refrigerant substantially constant in the place where it should be constant, and obviating the risk of flooding thereat, and to prevent audible vibration of the pipes or conduits as the refrigerant passes from point to point therein.

In refrigerating apparatus, especially when used for air conditioning, the refrigerant is often treated to lower its temperature at one place and then transmitted to another some distance off to produce the desired refrigerating eifect. The complete installation hundred feet of pipe, a considerable length of which is frequently disposed in vertical position. Whenthe refrigerant is travelling through such a length of pipe the movement thereof may become unsteady, due to various causes, and when it passes through a long conduit in a downward direction and the rate of flow is not enough to fill the pipe, cascading takes place and the impact at the end of the fall of the refrigerant in the pipe causes much disturbing noise.

A further object of the invention accordingly is to provide in a refrigerating system, preferably to deliver the refrigerant to a place in which water or like refrigerant absorbs heat, and an evaporator to which the water is returned to be chilled and used over, a suitable regulating appliance that causes the pipe for returning the refrigerant to the evaporator to be kept uniformly full, the flow therethrough maintained at an even rate and the level of the refrigerant in the evaporator kept virtually constant, with the result that surges and fluctuations in the flow' of the refrigerant and the danger of flooding the evaporator are eliminated, and the hammering note, which is the vibration of the pipe as if made by striking or tapping with a hammer, and all the unpleasant sounds accompanying same, are suppressed completely.

, The objects and advantages of the invention are fully set forth in the ensuing description which, taken with the drawing, presents several embodiments of the invention. The disclosure is, however, explanatory only and changes in various details of the construction and mode of operation may be made without departure from the principle of the invention.

On the drawing, Figure 1 shows one construction in which the invention is embodied, and

Figure 2 is a modification of same.

may thus include several comprising a conduitthis pipe results.

On the drawing the same numerals identify the same parts throughout.

In Figure l, at I a closed vessel called an evaporator is shown in which a liquid refrigerant,

such as water, undergoes a reduction in temperature. The refrigerant enters by way of a header having jet openings in the evaporator, the header forming the end of a supply pipe 2. A vacuum is created and maintained in the evaporator, so that some of the refrigerant is vaporized immediately upon entrance, and the vapor is removed by a, suitable device (not shown) through an opening 3'. The process of vaporization extracts heat from the remainder of the refrigerant and thus chills it. The cooled refrigerant is then delivered to a pipe 4, through which it is forced by a pump 5 to a suitable unit, such as a cooling coil outlined at 6. In this unit the water absorbs heat and becomes warmer and it is then returned to the evaporator through the pipe 2. The apparatus or unitt is often some distance off, or mounted at a considerable height above the evaporator I and the pipe 2 then may have a length of many feet. If no controlling device is present, then, whether the pipe 2 is-vertical or not, the flow of the refrigerant through the pipe 4, coil 6 and pipe 2 may not always be regular, but may pulsate somewhat due to momentary variations in the speed of the motor and the pump 5 for example,

- or any other cause; also if the coil 6 is above the evaporator and the pump stops or the circulation ceases for any other reason, the contents of the coil 6 will run down into the evaporator and flood it, and damage to the device for removing the vapor may ensue if any of the refrigerant goes out through the opening 3. Further, though the pump 5 can keep the pipe 4 filled when the unit 6 is higher than the evaporator, yet on the return of the water fromthe unit 6 to the evaporator, if the pipe 2 extends vertically through a sumcient distance without bends therein, and the flow of water is insuflicient to keep the pipe 2 filled, cascading results in this part of the system, and the occupants of adjoining rooms or compartments in the building containing the systemare apt to be annoyed greatly when hammering of the refrigerant in the pipe Therefore in line of pipe 2, near the evaporator l. ,a suitable casing 1 containing a valve 8 is inserted. This valve has an external stem 9 terminating in a head l0, and a spring H sur- 2 and vibration of rounds the stem between the head andthe casposition. This chamber I2 is connected by a pipe ll to the conduit 2 adjacent the valve 8,

but on the side toward the apparatus 6. Hence when the water flows through the pipe 2 in sufficient volume to fill this pipe the pressure of the column of water in the pipe 2 taking effect through the pipe I4 on the diaphragm l3 will move this valve toward open position so that the circulation will not be obstructed. On the other hand if there should be any tendency of the rate of flow in the pipe 2 to decrease, the pressure in this pipe will drop and so will the corresponding pressure in the chamber I2, thus enabling the spring H to move the valve 8 toward closed position. Of course means may be provided to adjust the force of the spring I l.

In the connection I4 is a casing l5 containing a valve IS with a protruding stem IT. This ste-m' carries a plunger l 8 the weight of which will nor-' mally close the valve. The plunger is in opera tive position with respect to a solenoid l9 connected with wires 20 to the circuit 2| of the electric motor 22 for the pump 5. This circuit has the usual switch 23 between the motor and the wires 24 ofthe source of supply, this switch being between the supply wires 24 and the junction points of the wires 20 with the motor circuit, so that when the switch is open the motor is stopped and the solenoid I8 is deenergized. The valve I 6 is therefore closed to prevent water from flowing into the evaporator I. But as soon as the switch 23 is closed so as to start up the motor, the solenoid l9 lifts the plunger I8 so as to open the connection l4 and expose the diaphragm 13 to the pressure of the water in th pipe 2.

The valve casing I 5 is connected to the pipe 2 between the valve 8 and the evaporator I also .by means of a branch 25, and in the line of this branch is a valve operated by av knob 26. This valve serves as a leak-oil valve so that the pressure of the water in the pipe 2 on the diaphragm l3 can be relieved when the valve I6 closes. The

valve 26 will be open enough to release the diaphragm when the valve l6 seats itself, but not enough to prevent the pressure of the refrigerant from opening the valve 8"when the valve I6 is open. Hence even though the coil 6 and pipe 2 might contain enough water to flli the evaporator, flooding cannot occur, because as soonas the operation is stopped by opening the switch 23, the valve l6 closes and the valve 8 follows and stops up the pipe 2. As long as the flow through I 2, instead of being connected to the pipe 2, is

united by a pipe 21 to the pipe 4 adjacent the discharge end of the pump 5. The valve 8 normally tends to close under the pressure of the spring H, but the pressure of the refrigerant in the pipe 4 will move this valve to open position. An adjustable stop-screw 28 determines the extent of the opening movement; being held in desired position by a lock nut 28. Of course, whenever the system is shut down and the pump is not operating so that no water under pressure can flow from the pump 5 to a cooling coil, for

The arrangement of parts shown in Figure I is particularly useful when employed with closed coils 6 high above the evaporator. The arrangement shown in Figure 2 can also be used when coil 6 is located at some height, but that of Figure 1 is better for this purpose. The apparatus of Figure 2 can be used to advantage with coil 6 lower-say up to fifty feet elevation above the evaporator. The return water pipe 2 is maintained full of water throughout its entire length, regardless of the vertical distance through which this pipe drops to the evaporator I. Hence .surges of the refrigerant due to the changing,

amount of the water in the return pipe and vibration due to the cascading of water in the return pipe 5 when the latter is partly empty never originate.

From the foregoing description it will be clear I that the invention is well adapted to serve the purpose for which it is intended, is very simple and effective in practice, and entails no great cost to install and operate.

I claim:

1. The combination with a refrigerating system having an evaporator and a continuous conduit removing chilled refrigerant therefrom and returning warmed refrigerant thereto, of apparatus for maintaining said conduit substantial- 1y filled with refrigerant and for preventing flooding of the evaporator, said apparatus comprising a pump to force refrigerant from the evaporator through the conduit, a check valve in the conduit at the pump discharge to prevent back-flow of refrigerant through .the pump and into the evaporator, and. a device responsive to the pressure of the refrigerant in the conduit to effect a desired degree of obstruction of the conduit near its entrance to the evaporator, said device to cause complete obstruction of said conduit when said pressure fails thereby trapping refrigerant in the conduit between said device and said check valve.

2. The combination with a refrigerating system having an evaporator, a delivery conduit conducting chilled refrigerant from the evaporator to a substantially higher level than the evaporator and a return conduit discharging warmed refrigerant from the higher level .to the evaporator, of apparatus for maintaining said conduits substantially filled with refrigerant and for preventing flooding of the evaporator comprising a pump to force the refrigerant to the higher level, a valve in the delivery conduit to'prevent draining of the refrigerant and flooding of the evaporator thereby, and a device in the return conduit near its lowest extremity to control the refrigerant discharge therethrough in response to variations in the static pressure head of the refrigerant in the return conduit and being adapted to completely stop flow of refrigerant when said pressure head falls-below a predetermined value thereby'to prevent emptying of the return conduit.

GEORGE H. WOODARD. 

